A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.
The present invention relates generally to devices for entering data into a computer.
The most common way for a person to interact with a computer is through a keyboard. The standard computer keyboard is the QWERTY keyboard, first developed in the 19th century for use with mechanical typewriters. The QWERTY keyboard, sometimes known by its full name of QWERTYUIOP, has keys spread out in horizontal rows across the surface of the keyboard. Imprinting a character is achieved by depressing the corresponding key on the keyboard.
The QWERTY keyboard was designed to provide the maximum physical separation between the most frequently used letters of the alphabet, and thus reduce the likelihood of keys jamming during typing. The layout of keys that resulted is not particularly logical; the name of the keyboard is taken from the ordering of the first row of keys.
An alternate type of QWERTY keyboard is the Dvorak keyboard. The Dvorak keyboard has the most frequently used keys placed where they are most accessible to the typist. This arrangement is well known for allowing typists to attain greater efficiency and faster typing speeds relative to the old QWERTY keyboard.
The QWERTY keyboard, nevertheless, remains the standard keyboard despite the greater efficiencies of the Dvorak keyboard. One impediment to adopting the Dvorak keyboard is its similarity with the QWERTY keyboard; a typist who is skilled at typing on either a QWERTY or a Dvorak keyboard can type only with difficulty on the other. This problem of incompatibility appears to happen because both the Dvorak and QWERTY keyboards are mere variations of the same basic keyboard. It follows that the same motor centers of the brain needed to type on a QWERTY keyboard are also needed to type on a Dvorak keyboard. The finger motions needed to type on either keyboard are similar. This similarity causes the human mind to have trouble keeping the motor control needed to type on either one of the keyboards separate. Using both keyboards skillfully requires too much of a typist because the typing skills interfere. It is common knowledge that a typist can transfer between the QWERTY and Dvorak keyboards only with great difficulty.
The skill required to type on both the QWERTY and Dvorak keyboards is difficult to learn and easy to forget. A person must practice for hundreds of hours to become proficient in typing on either the Dvorak or QWERTY keyboard. These difficulties result from the extreme complexity of motion required to type efficiently; the typist must learn and retain the trajectory between each key and every other key on the keyboard covered by a given finger. This rote learning is quickly forgotten if not practiced regularly.
Special characters compound the complexity of typing on a QWERTY or Dvorak keyboard. A typist often must type characters other than alphanumeric characters--mathematical, cyrillic, and oriental symbols and characters are common examples. Customizing a conventional keyboard to accommodate these additional symbols is easy to do using additional shift keys such as the "control" and "alternate" keys. These additional shift keys, however, create whole new levels of complexity for typing. A typist must learn how to move efficiently between the keys having these new characters. As a result, learning these new keystrokes is as complex as learning how to type the alphanumeric characters. Moreover, there is no standard by which to add these additional characters to a computer keyboard. Each computer maker and, indeed, every software maker can assign different characters to the "alternate" and "control" shift keys. The conventional keyboard thus reduces even a skilled typist to using a "hunt and peck" method of data entry as a mattter of necessity--the number of times that special characters need to be typed do not permit anyone to learn and retain the knowledge needed to type them efficiently.
Another disadvantage associated with the conventional, QWERTY-type keyboard is the increase in the number of inexperienced typists who are using keyboards as a result of office automation. The proliferation of personal computers, hand calculators and other forms of automated office equipment have required that virtually everyone enter data into a computer through a keyboard. However, very few individuals have the time to become proficient typists. Hence, most typing involves the "hunt and peck" and "hunt and check" methods, defined herein as selecting one key at a time based on some template overlay. This form of data entry is inefficient and frustrates the ability of office automation to increase productivity.
Yet another liability of the conventional QWERTY-type keyboard is its size. The conventional keyboard requires a certain minimum surface area in which to spread out the keys since each key must have a certain minimum size to be touched.
The size of the QWERTY keyboard is now a concern. The minimum size of a computer has been decreasing for some time. One limit that was reached in the personal computer was the size required for a video display tube (VDT)--the last vacuum tube commonly used in consumer electronics. Recent advances in solid state displays, however, eliminate the necessity of using a VDT for the display screen. Microprocessor and microelectronic technology, together with solid state video display technology, allow computers that are quite small to be produced--a personal computer can fit in a package no larger than a small book, rather than the several cubic feet that is now so common. It is the keyboard--that anachronism from the 19th century--that now sets the lower limit of the practical size of a personal computer.
There is another type of keyboard for entering data into a computer--the chord keyboard. In contrast to the QWERTY and Dvorak keyboards, the chord keyboard does not require a typist to memorize a large number of finger trajectories to enter data. The chord keyboard has a small number of keys, usually between five and twenty-five. In addition to generating characters by pressing a single key, a chord keyboard also generates a character when two or more keys are simultaneously depressed--in contrast to the conventional, QWERTY-type keyboard which was specifically designed to avoid a typist depressing multiple keys at the same time.
Chord keyboards have many desirable attributes that are well known in the art. For example, a typist can learn to "touch type" on a chord keyboard with 30-60 hours of practice. One reason for this shorter learning period is that the relatively small number of keys on a chord keyboard reduces the errors caused by fingers getting out of alignment the way they easily can on a QWERTY keyboard. Writing is something done by one hand; a chord keyboard also can be operated by one hand. Typing on a chord keyboard therefore can be more natural than typing on a conventional, QWERTY-type keyboard. There is no need for the typist to memorize many complex finger trajectories in order to use a chord keyboard.
Another known advantage of a chord keyboard is its compatibility with the QWERTY and Dvorak keyboards. The type of motor control needed to type on a chord keyboard compared to that needed to type on a conventional, QWERTY-type keyboard is such that a typist apparently experiences little or no difficulty in changing back and forth between them. It should therefore be possible for the chord keyboard to coexist with the QWERTY keyboard.
The chord keyboard has another attribute that makes it particularly important now--chord keyboards are smaller in size. The layout for 5-25 keys requires substantially less surface area than that needed to layout the 30-100+ keys found on typewriters, personal computers and word processors. Moreover, customizing a chord keyboard involves the relatively simple process of assigning new characters to previously unused combinations of keys or adding additional shift keys. Learning to touch type these new key arrangements is also less time consuming than on a conventional QWERTY-type keyboard. The chord keyboard has great promise for reducing the size of the lap top computer and for increasing productivity and typing speed.
There are problems, however, in realizing the promise of the chord keyboard. The art contains many examples of chord keyboards, but none have succeeded in unlocking the enormous potential inherent in the basic concept of the chord keyboard.
One disadvantage of the chord keyboard is that a typist must be assisted to find the keys on the keyboard. A chord keyboard can leave the typist without any way to know which combination of keys will generate a particular character. In contrast, the QWERTY keyboard displays all the characters all the time; the typist is invited to find characters and to press the character keys on the keyboard. A chord keyboard is to a conventional, QWERTY keyboard as a command driven software program is to a menu driven program; a command driven program does not tell the user which commands are available, whereas a menu driven program does by displaying commands on a menu. The chord keyboard hides its characters, whereas a QWERTY keyboard always has them in full display. Hence, the QWERTY keyboard is more "user friendly" even though it is more difficult to use.
Another disadvantage of a chord keyboard is the extra work needed to generate each character. A conventional, QWERTY-type keyboard requires only one finger motion to generate a character. A chord keyboard, by definition, requires depressing several keys for at least some characters. This additional work can become tiring.
Another disadvantage of the chord keyboard is that it does not have an ergonomic design. Indeed, chord keyboard designs appear to have been made without ever considering the stress that they place on the typist. Previous chord keyboards can require the typist to engage in hand motions that are highly abnormal such as, for example, keeping the hand pressed flat against the keyboard or requiring the typist to generate a character by lifting the finger rather than by depressing it. The human hand is adapted to grabbing and pulling objects--not repeatedly moving fingers up and down across a flat keyboard surface or repeated flicking buttons to generate characters. The lack of an ergonomically correct design for a chord keyboard limits its acceptance and its utility.
A disadvantage shared by the conventional, QWERTY keyboard and previous chord keyboards is a matter of health called repetitive stress injury (RSI), a malady that has been traced directly to doing repetitive work in a way that the human body is not designed to do. RSI is a multi-faceted problem, but some of its elements related to using keyboards involve sitting at a console bound--or desk bound--keyboard with a relatively fixed position of the back, neck, arms, and fingers, for extended periods of time. The cure for RSI is to redesign the work to be more natural for the worker, i.e., to make the equipment more ergonomic so that the repeated activity does not stress the body. Chord keyboards in the prior art, had they been more utilized, would have been particularly prone to inflicting RSI on the typist due to the larger number of keystrokes required to enter the same data.
Another disadvantage shared by both the QWERTY keyboard and the chord keyboard is that neither have been integrated into the general cybernetic interface required for man-machine interaction. For example, a personal computer typically includes a separate mouse or other device to move the pointer on the display. The objective is to point at "icons" on the display which are then selected using a separate "click on" button. The "click and drag" feature used on the Apple Macintosh, Macintosh II and IBM PS2 personal computers make heavy use of the pointing device which are required by the graphical user interface. Neither machine, however, is equipped with a keyboard with an all purpose user control. As a result, a typist must inefficiently shift back and forth between the keyboard and the pointing device.
The disadvantages associated with the chord keyboard have prevented its acceptance where most needed--the commercial marketplace. Now, however, those disadvantages must be overcome so that personal computers can become fully portable. There is thus an urgent need in the art for a small, portable chord keyboard that is ergonomically designed to counter repetition stress injury as well as minimize the time needed to learn new keystrokes. It is further advantageous that the chord keyboard provide all the data input required by the computer in an ergonomically correct manner. Only then can the potential of the chord keyboard be realized in commercial practice.
The ergonomic disadvantages of prior chord keyboards may be summarized as:
1) Too few keys, resulting in too many fingers being used to generate each desired character; chord keyboard typing was therefore very tiring. PA1 2) Too many finger press positions, requiring very fine motor control; errors were easily made. PA1 3) No logical arrangement of characters so that chord typing was difficult to learn. PA1 4) No visual cues indicating what keys to press to generate a given character. PA1 5) Unnatural finger positions were required to type each character.